1 // Allocator traits -*- C++ -*-
2
3 // Copyright (C) 2011-2021 Free Software Foundation, Inc.
4 //
5 // This file is part of the GNU ISO C++ Library. This library is free
6 // software; you can redistribute it and/or modify it under the
7 // terms of the GNU General Public License as published by the
8 // Free Software Foundation; either version 3, or (at your option)
9 // any later version.
10
11 // This library is distributed in the hope that it will be useful,
12 // but WITHOUT ANY WARRANTY; without even the implied warranty of
13 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 // GNU General Public License for more details.
15
16 // Under Section 7 of GPL version 3, you are granted additional
17 // permissions described in the GCC Runtime Library Exception, version
18 // 3.1, as published by the Free Software Foundation.
19
20 // You should have received a copy of the GNU General Public License and
21 // a copy of the GCC Runtime Library Exception along with this program;
22 // see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
23 // <http://www.gnu.org/licenses/>.
24
25 /** @file ext/alloc_traits.h
26 * This file is a GNU extension to the Standard C++ Library.
27 */
28
29 #ifndef _EXT_ALLOC_TRAITS_H
30 #define _EXT_ALLOC_TRAITS_H 1
31
32 #pragma GCC system_header
33
34 # include <bits/alloc_traits.h>
35 #if __cplusplus < 201103L
36 # include <bits/allocator.h> // for __alloc_swap
37 #endif
38
_GLIBCXX_VISIBILITY(default)39 namespace __gnu_cxx _GLIBCXX_VISIBILITY(default)
40 {
41 _GLIBCXX_BEGIN_NAMESPACE_VERSION
42
43 /**
44 * @brief Uniform interface to C++98 and C++11 allocators.
45 * @ingroup allocators
46 */
47 template<typename _Alloc, typename = typename _Alloc::value_type>
48 struct __alloc_traits
49 #if __cplusplus >= 201103L
50 : std::allocator_traits<_Alloc>
51 #endif
52 {
53 typedef _Alloc allocator_type;
54 #if __cplusplus >= 201103L
55 typedef std::allocator_traits<_Alloc> _Base_type;
56 typedef typename _Base_type::value_type value_type;
57 typedef typename _Base_type::pointer pointer;
58 typedef typename _Base_type::const_pointer const_pointer;
59 typedef typename _Base_type::size_type size_type;
60 typedef typename _Base_type::difference_type difference_type;
61 // C++11 allocators do not define reference or const_reference
62 typedef value_type& reference;
63 typedef const value_type& const_reference;
64 using _Base_type::allocate;
65 using _Base_type::deallocate;
66 using _Base_type::construct;
67 using _Base_type::destroy;
68 using _Base_type::max_size;
69
70 private:
71 template<typename _Ptr>
72 using __is_custom_pointer
73 = std::__and_<std::is_same<pointer, _Ptr>,
74 std::__not_<std::is_pointer<_Ptr>>>;
75
76 public:
77 // overload construct for non-standard pointer types
78 template<typename _Ptr, typename... _Args>
79 static _GLIBCXX14_CONSTEXPR
80 std::__enable_if_t<__is_custom_pointer<_Ptr>::value>
81 construct(_Alloc& __a, _Ptr __p, _Args&&... __args)
82 noexcept(noexcept(_Base_type::construct(__a, std::__to_address(__p),
83 std::forward<_Args>(__args)...)))
84 {
85 _Base_type::construct(__a, std::__to_address(__p),
86 std::forward<_Args>(__args)...);
87 }
88
89 // overload destroy for non-standard pointer types
90 template<typename _Ptr>
91 static _GLIBCXX14_CONSTEXPR
92 std::__enable_if_t<__is_custom_pointer<_Ptr>::value>
93 destroy(_Alloc& __a, _Ptr __p)
94 noexcept(noexcept(_Base_type::destroy(__a, std::__to_address(__p))))
95 { _Base_type::destroy(__a, std::__to_address(__p)); }
96
97 static constexpr _Alloc _S_select_on_copy(const _Alloc& __a)
98 { return _Base_type::select_on_container_copy_construction(__a); }
99
100 static _GLIBCXX14_CONSTEXPR void _S_on_swap(_Alloc& __a, _Alloc& __b)
101 { std::__alloc_on_swap(__a, __b); }
102
103 static constexpr bool _S_propagate_on_copy_assign()
104 { return _Base_type::propagate_on_container_copy_assignment::value; }
105
106 static constexpr bool _S_propagate_on_move_assign()
107 { return _Base_type::propagate_on_container_move_assignment::value; }
108
109 static constexpr bool _S_propagate_on_swap()
110 { return _Base_type::propagate_on_container_swap::value; }
111
112 static constexpr bool _S_always_equal()
113 { return _Base_type::is_always_equal::value; }
114
115 static constexpr bool _S_nothrow_move()
116 { return _S_propagate_on_move_assign() || _S_always_equal(); }
117
118 template<typename _Tp>
119 struct rebind
120 { typedef typename _Base_type::template rebind_alloc<_Tp> other; };
121 #else // ! C++11
122
123 typedef typename _Alloc::pointer pointer;
124 typedef typename _Alloc::const_pointer const_pointer;
125 typedef typename _Alloc::value_type value_type;
126 typedef typename _Alloc::reference reference;
127 typedef typename _Alloc::const_reference const_reference;
128 typedef typename _Alloc::size_type size_type;
129 typedef typename _Alloc::difference_type difference_type;
130
131 _GLIBCXX_NODISCARD static pointer
132 allocate(_Alloc& __a, size_type __n)
133 { return __a.allocate(__n); }
134
135 template<typename _Hint>
136 _GLIBCXX_NODISCARD static pointer
137 allocate(_Alloc& __a, size_type __n, _Hint __hint)
138 { return __a.allocate(__n, __hint); }
139
140 static void deallocate(_Alloc& __a, pointer __p, size_type __n)
141 { __a.deallocate(__p, __n); }
142
143 template<typename _Tp>
144 static void construct(_Alloc& __a, pointer __p, const _Tp& __arg)
145 { __a.construct(__p, __arg); }
146
147 static void destroy(_Alloc& __a, pointer __p)
148 { __a.destroy(__p); }
149
150 static size_type max_size(const _Alloc& __a)
151 { return __a.max_size(); }
152
153 static const _Alloc& _S_select_on_copy(const _Alloc& __a) { return __a; }
154
155 static void _S_on_swap(_Alloc& __a, _Alloc& __b)
156 {
157 // _GLIBCXX_RESOLVE_LIB_DEFECTS
158 // 431. Swapping containers with unequal allocators.
159 std::__alloc_swap<_Alloc>::_S_do_it(__a, __b);
160 }
161
162 template<typename _Tp>
163 struct rebind
164 { typedef typename _Alloc::template rebind<_Tp>::other other; };
165 #endif // C++11
166 };
167
168 _GLIBCXX_END_NAMESPACE_VERSION
169 } // namespace __gnu_cxx
170
171 #endif
172